[PATCH 5.19 003/101] perf record: Fix cpu mask bit setting for mixed mmaps

From: Greg Kroah-Hartman
Date: Mon Oct 03 2022 - 03:14:00 EST


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

[ Upstream commit ca76d7d2812b46124291f99c9b50aaf63a936f23 ]

With mixed per-thread and (system-wide) per-cpu maps, the "any cpu" value
-1 must be skipped when setting CPU mask bits.

Prior to commit cbd7bfc7fd99acdd ("tools/perf: Fix out of bound access
to cpu mask array") the invalid setting went unnoticed, but since then
it causes perf record to fail with an error.

Example:

Before:

$ perf record -e intel_pt// --per-thread uname
Failed to initialize parallel data streaming masks

After:

$ perf record -e intel_pt// --per-thread uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.068 MB perf.data ]

Fixes: ae4f8ae16a078964 ("libperf evlist: Allow mixing per-thread and per-cpu mmaps")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Athira Rajeev <atrajeev@xxxxxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20220915122612.81738-2-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 708880a1c83c..7fbc85c1da81 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -3344,6 +3344,8 @@ static int record__mmap_cpu_mask_init(struct mmap_cpu_mask *mask, struct perf_cp
return 0;

perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
+ if (cpu.cpu == -1)
+ continue;
/* Return ENODEV is input cpu is greater than max cpu */
if ((unsigned long)cpu.cpu > mask->nbits)
return -ENODEV;
--
2.35.1